USO0RE40433E
(19) United States (12) Reissued Patent
(10) Patent Number: US RE40,433 E (45) Date of Reissued Patent: Jul. 15, 2008
Schmon (54)
(56)
NOZZLE ARRANGEMENT FOR A PAINT SPRAY GUN
References Cited U.S. PATENT DOCUMENTS
(75) Inventor: EWald Schmon, Grafenberg (DE) 2,269,057 A 4,545,536 A 4,917,300 A
(73) Assignee: Sata GmbH & Co. KG, KornWestheim
(DE) (21) App1.N0.: 11/022,425 (22) Filed:
5,344,078 A 5,435,491 A
Dec. 21, 2004 FR
Reissue of:
(30)
Mar. 25, 1997
App1.N0.:
08/357,014
Filed:
Dec. 16, 1994
2 444 501
7/1980
Bianco; Fleit Gibbons Gutman Bongini & Bianco P.L.
(57) (51)
Fritz et a1. ................ .. 239/296 Sakuma .......... .. 239/DIG. 14X
Primary Examineristeven J. Ganey (74) Attorney, Agent, or FirmiMartin Fleit; Paul D.
Foreign Application Priority Data
Oct. 5, 1994
9/1994 7/1995
* cited by examiner
5,613,637
Issued:
* *
FOREIGN PATENT DOCUMENTS
Related US. Patent Documents
(64) Patent No.:
1/1942 Jenkins 10/1985 Avidon 4/1990 Gloviak et a1.
ABSTRACT
(DE) ..................................... .. G 9416 015
Int. Cl. B05B 7/04 B05B 1/06
A nozzle structure for a paint spray gun, is comprised of a central outlet for paint, an annular slot surrounding the cen
(2006.01) (2006.01)
tral outlet, the annular slot being connected inside the nozzle
(52)
US. Cl. ...................... .. 239/296; 239/518; 239/526;
(58)
Field of Classi?cation Search ................ .. 239/290,
239/600; 239/DIG. 14
239/296, 300, 600, DIG. 14, 525, 526, 461,
structure via an annular duct to a number of virtually axially parallel bores, the bores being situated on at least one circle about a central axis of the nozzle structure, apparatus for
providing[,] compressed air via the bores for delivery to the annular duct, and an air [reversing] de?ection disk located inside the annular duct and opposite the bores.
239/518
See application ?le for complete search history.
2/
26 Claims, 2 Drawing Sheets
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US RE40,433 E
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US RE40,433 E
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FIG. 2 47
US RE40,433 E 1
2
NOZZLE ARRANGEMENT FOR A PAINT SPRAY GUN
geneously as possible and accidental losses of quality are
avoided during production. In accordance with an embodiment of the invention a nozzle structure for a paint spray gun is comprised of a cen
Matter enclosed in heavy brackets [ ] appears in the original patent but forms no part of this reissue speci?ca
tral outlet for paint, an annular slot surrounding the central outlet, the annular slot being connected inside the nozzle
tion; matter printed in italics indicates the additions made by reissue.
structure via an annular duct to a number of virtually axially parallel bores, the bores being situated on at least one circle about a central axis of the nozzle structure, apparatus for
FIELD OF THE INVENTION The invention relates to a nozzle arrangement for a paint spray gun, as well as the paint spray gun.
providing compressed air via the bores for delivery to the annular duct, and an air [reversing] de?ection disk located inside the annular duct and opposite the bores.
BACKGROUND TO THE INVENTION
A nozzle arrangement for a paint spray gun is described in German Utility Model G 90 01 265.8. The nozzle arrange ment described in that document has a central outlet for the paint which can be closed with an axially extending pin. The paint ?ows pressureless from a ?uid container to this seal able outlet. The outlet is surrounded by an annular slot out of
which a circular air jet of high velocity ?ows, which thereby sucks paint out of the outlet, atomizes it and carries it along,
BRIEF INTRODUCTION TO THE DRAWINGS
An embodiment of the invention shall be described in
greater detail with reference to the accompanying drawings,
20
as a result of which a circular jet consisting of paint particles is formed.
DETAILED DESCRIPTION OF THE INVENTION
Laterally of the jet direction, the nozzle arrangement has two protruding horns, horn air jets of which are directed
25
diagonally and in the same direction to the direction of ?ow of and into the circular jet, which deformed it. To control the horn air, the nozzle arrangement has, on both sides of the outlet in the direction of the horns, two or more control bores
through which air passes and impacts the horn air jets and
30
thus controls them. Both the annular slot and the control bores are supplied with air from the same air chamber, namely an annular duct
inside the nozzle arrangement. This annular duct is supplied with compressed air from supply bores which are located in a paint nozzle and the axes of which are arranged parallel
35
and equidistant on a circle around the axis of the nozzle
arrangement. A disadvantage of the arrangement described is that the air does not ?ow uniformly into the annular slot via the
40
supply bores arranged about the periphery inside the nozzle
45
in which the bores are also located, and minimums in between.
about colinear with these control bores and, as a result, the horn air is affected too greatly in an undesirable manner, which in turn changes the jet pattern in an undesirable man ner. The spray result thus depends on the relative position of the air cap having the horns and control bores relative to the
paint nozzle which has the supply bores. However, the posi tion of the paint nozzle screwed into the housing of the paint
compressed air (via a valve arrangement 32) and the outlet 3 (via a pin control device 33) are simultaneously released for the paint by means of an operating lever 31. The paint ?ows from the ?uid container (not shown), without pressure support, to the outlet 3 and passes out there when the pin 7 is pulled back. Compressed air ?ows simultaneously via a con duit system to the annular slot 5 which surrounds the outlet 3
sucks paint out of the outlet 3, which is then atomized and carried along due to the quick-?owing air while forming a
circular jet. The circular jet is pressed together by two horn
whereby peaks occur in the angular area of the annular slot,
In addition, this arrangement has the disadvantage that the air from the supply bores reaches directly into the control bores for the horn air, depending on the angular position of the paint nozzle having the bores relative to the housing or air cap of the paint spray gun, when the supply bores are
The paint spray gun shown in the Figure is comprised essentially of a housing 30 which includes an upper part with a suspension hook and a handle 45. A compressed-air supply conduit is attached to the underside of the handle 45, an air choke 40 can be built in to decrease the pressure when the air enters, primarily in low-pressure guns; a ?uid container for the paint is mounted on the top at a connection 46. The
and produces a vacuum directly at the outlet 3. This vacuum
arrangement, as a result of which the air/paint mixture is not
distributed as uniformly as possible in the circular jet. If the air pressure were measured along the periphery of the annu lar slot, then an almost sinusoidal modulation would result,
in which: FIG. 1 is a cross-section through a paint spray gun, and FIG. 2 is the nozzle arrangement used in the paint spray gun of FIG. 1, in section and partial cross-section.
50
air jets which pass out of the horns 21 forming a part of the nozzle arrangement 1, in such a way that the circular jet is deformed into a ?at jet. The air ?ow from the outlet holes 20 of the horns 21 is, in turn, affected by control bores 22 which are not provided with reference numbers in FIG. 1. To describe the nozzle arrangement 1 in greater detail, reference is made to FIG. 2 below, in which axis 4 refers to the central axis of the nozzle arrangement, in which the pin 7 is also located and the direction of the ?ow of the main jet
direction of the air/paint mixture passing out of the nozzle, as shown by arrow 12. 55
The nozzle arrangement 1 shown in FIG. 2 is comprised of paint nozzle 11, which is screwed into a nozzle insert 10 (see FIG. 1) of the paint spray gun 2 via an external thread 34
and which contains axially parallel air bores 18. The paint
60
spray gun is determined by the starting out of its thread and
nozzle 11 is surrounded by an air cap 16 which is screwed together with an external thread of the nozzle insert 10 with aid of a cap nut (not shown). A middle section 35 of a larger diameter adjoins the exter
nal thread 34 of the paint nozzle 11 for screwing into the nozzle insert 10, the middle section being hollow on the
thus a great extent accidental, so that some of the guns pro
duced exhibit undesirable paint coat properties.
inside to admit the pin 7 and having an annular recess 47 on
SUMMARY OF THE INVENTION
Thus, it is an object of the invention to provide a nozzle arrangement such that the annular air jet ?ows out as homo
65
its rear facing the external thread 34. Six axially parallel, identical bores 8, arranged on a circle about the axis 4, extend from this recess at a distance of 600 through the
US RE40,433 E 3
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middle section 35 of the paint nozzle 11. Finally, the paint
supply bores 19 in the horns 21 of the air cap 16. The outlet
nozzle 11 also has a front area 13 Which extends from the
holes are directed doWnWard or upWard to the extension of
outlet of the bores 8 to the front end of the paint nozzle 11. This front area is comprised of a cylindrical part 36 Whose diameter is small enough to keep the front end of the bores 8 clear. A further, disk-shaped cylindrical area of a larger
the axis 4 in direction of How 12. The inner compressed air ?oW reaches the six bores 8 inside the paint nozzle 11 in the annular duct 6. This compressed air ?oW hits the air [revers
ing] de?ection plate 9, Which completely covers bores 8, at a high speed. Thus, a very turbulent ?oW, Which also has con siderable tangential components and distributes the com
diameter, Which is relatively thin and is called an air [revers
ing] de?ection disk 9 beloW, adjoins this cylindrical area 36.
pressed air in peripheral direction, results betWeen the outlet of bores 8 and the air [reversing] de?ection plate 9. The
The diameter of the air [reversing] de?ection disk 9 is mea sured in such a Way that, seen from the front, the bores 8 are
compressed air then ?oWs through the narroW area of the
completely covered. The furthermost front area of the paint
annular duct 6 past the air [reversing] de?ection disk 9 and hits the plane annular surface 17. A relatively strong turbu lence results, in turn, due to the sudden change in direction
nozzle 11 ?nally divides into a conical taper 23 at a ?rst
angle of about 30° to the axis 4, a conical taper 24 adjacent thereto at a second, smaller angle and a cylindrical end area
and thus a further homogenization of the pressure ratios.
25 adjacent thereto. The air cap 16 surrounding the paint nozzle 11 When assembled is essentially symmetric to axis 4 on the inside. HoWever, it has tWo horns 21 Which are diametrically oppo site one another and protrude beyond the annular slot 5 and outlet 3 in the direction of How 12. TWo supply bores 19 extend from the rear of the air cap 16 to outlet holes 20 in the horns 21, Whereby each horn 21 has tWo holes 20. Holes 20 are directed in such a Way that they point to the axis 4 in the direction of How 12 toWard the annular slot 5, that is, they can affect the air Which has already passed out of the annular slot 5. The air cap 16 has a middle region Which ends at the
Finally, the compressed air passes through the rest of the annular duct 6 Which continues to taper more and more and then has no more corners or edges acting as a How [reverser] 20
25
control bores 22 Which are arranged on a line betWeen the
from the outlet holes 20, also in a knoWn manner. The in?u ence of the horn air takes place again in a knoWn manner
through the control bores 22, hoWever, signi?cantly more 35
plate 9 is located betWeen them. Thus, in the nozzle arrange ment of the invention, it is inconsequential What the relative position of paint nozzle 11 and air cap 16 is, since the air 40
is only opened by the control bores 22. The outside Wall 15 of the annular duct 6 tapers from the bores 8 to the annular slot 5, at ?rst continuously beyond the area of the air revers ing disk 9. A discontinuous jump then takes place on a plane
45
annular surface 17, Which is directed essentially at right angles to the axis 4. The outside Wall 15 then tapers continu ously again and changes in the area of the middle, that is of the annular slot 5, continuously into a run parallel to the axis
4, Without a sharp bend taking place. The inside Wall 14, formed by the paint nozzle 11, With
50
55
angles (areas 23 and 24) and then runs cylindrically (area
structure via an annular duct having a downstream end con nected to the annular slot and an upstream end connected to situated on at least one circle about a central axis of the
the paint nozzle 11. 60
By actuating the operating lever 31, the pin 7 is pulled back opposite to the direction of How 12 and, at the same
holes 20 via bores 18 in the nozzle insert 10 and the tWo
since these react more sensitively to variations in pressure. I claim: 1. A nozzle structure for a paint spray gun, comprising a central outlet for paint, an annular slot surrounding the cen
a number of virtually axially parallel bores, the bores being
25). The innermost area of the air cap 16 thus forms the annular slot 5 With the cylindrical area 25 at the front end of
time, the nozzle insert 10 is acted upon by tWo compressed air ?oWs, Which can be controlled separately on the paint spray gun. The outer compressed air ?oW reaches the outlet
of the air [reversing] de?ection disk 9. Due to the fact that uniform spray jet geometries result, a spray gun or nozzle arrangement of this type can also be made more quickly and With less expense. The nozzle arrangement described can be used both in
tral outlet, the annular slot being connected inside the nozzle
one piece, also tapers adjacent to the air [reversing] de?ec
The nozzle arrangement of the invention functions as fol loWs after it has been attached to a paint spray gun.
passing out of bores 8 is alWays prevented, With certainty, from ?oWing directly against the control bores 22 by means
high-pressure and loW-pressure paint spray guns. HoWever, it does have special advantages in modern loW-pressure guns
Which the air [reversing] de?ection disk 9 can be made in tion disk 9, namely, as described above, at tWo different
homogeneously, more reliably and more uniformly than With the knoWn nozzle arrangements. This is due to the fact that a straight alignment of the control bores 22 With bores 8
is no longer possible, because the air [reversing] de?ection
The assembled arrangement is comprised of paint nozzle 11 and air cap 16, as shoWn in FIG. 2, and forms an annular duct 6 betWeen the outside of the front area 13 (With 36) of the paint nozzle 11 and the inside of the air cap 16. This annular duct 6 begins at the end of bores 8 and extends past the air reversing disk 9 to the annular slot 5. To the outside, it
ing a circular jet. The How velocity is increased by the air duct 6 tapering in the direction of the annular slot 5, that is, an optimum con version of the fall in pressure takes place from the air duct 6 to the ambient pressure in velocity. The circular jet thus formed is affected by the horn air
annular slot 5. This middle region is passed through by four tWo horns 21, that is, their air How can again affect the horn air coming out of the outlet holes 20 of horns 21. In the region of the inside control bores 22, the inside Wall of air cap 16 (Which Will be described later as outside Wall 15 of the annular duct 6) curves continuously until it is parallel to axis 4. Thus, there is no sharp transition here.
de?ector, but is kept as smooth and continuous as possible in order to attain a certain laminating of the How. The air ?oW, almost completely homogenized in this Way, passes out of the annular slot 5, sucks the paint out of the outlet 3 in a knoWn manner, atomizes it and carries it along While form
65
nozzle structure, means for providing compressed air via the bores for delivery to the upstream end of the annular duct, and an air [reversing] de?ection disk located inside the annu lar duct and opposite the bores for producing at the upstream end of the annular duct a ?rst area of turbulence in the ?ow ofairfrom the bores to the annular slot. 2. A nozzle structure [as de?ned in claim 1] for a paint spray gun, comprising a central outlet for paint, an annular
slot surrounding the central outlet, the annular slot being connected inside the nozzle structure via an annular duct to
US RE40,433 E 5
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a number of virtually axially parallel bores, the bores being
bores at the periphery of the nozzle insert, an air cap forming an outside Wall of the annular duct containing tWo diametri
situated on at least one circle about a central axis of the
cally opposite, axially parallel supply bores, tWo diametri
nozzle structure, means for providing compressed air via the bores for delivery to the annular duct, and an air de?ection disk located inside the annular duct and opposite the bores, wherein said nozzle structure is comprised of a paint nozzle
cally opposite horns containing outlet holes, the air bores being connected to the supply bores, the supply bores being connected to the outlet holes, the outlet holes being directed
containing the bores, the air [reversing] de?ection disk is
to the central axis in a direction of How toWard the number slot. 13. A nozzle structure as de?ned in claim 10, Wherein the
round and is in one piece With the paint nozzle that contains the bores, the nozzle structure containing a round nozzle insert for retaining the nozzle arrangement by means of threads, a front region of said paint nozzle forming, in a direction of paint How, an inside Wall of the annular duct, an outside Wall of the annular duct being formed by an air cap Which is attachable to the nozzle insert.
inside Wall of the annular duct tapers conically in a direction
of the air [reversing] de?ection disk, starting at a ?rst angle, folloWing at a second, smaller angle and ?nally being cylin drical to form an inside Wall of the annular slot.
14. A nozzle structure [as de?ned in claim 1] for a paint
3. A nozzle structure as de?ned in claim 2, in Which an
spray gun, comprising a central outlet for paint, an annular
outside Wall of the annular duct tapers continuously from the
slot surrounding the central outlet, the annular slot being
bores to the annular slot and curves continuously in the
connected inside the nozzle structure via an annular duct to
region of the annular slot until said Wall is parallel With the central axis.
a number ofvirtually axially parallel bores, the bores being
4. A nozzle structure as de?ned in claim 3, Wherein the continuous tapering of the outside Wall in a direction toWard
situated on at least one circle about a central axis of the 20
the air [reversing] de?ection disk is discontinuously inter rupted by a plane annular surface oriented at almost right angles to the central axis. 5. A nozzle structure as de?ned in claim 2, Wherein the
25
nozzle structure, means for providing compressed air via the bores for delivery to the annular duct, and an air de?ection disk located inside the annular duct and opposite the bores, Wherein the inside Wall of the annular duct tapers conically in a direction of the air reversing disk, starting at a ?rst
angle, folloWing at a second, smaller angle and ?nally being
nozzle insert has axially parallel horn air bores at the periph ery of the nozzle insert, the air cap containing tWo diametri
cylindrical to form an inside Wall of the annular slot.
cally opposite, axially parallel supply bores, tWo diametri
spray gun, comprising a central outlet for paint, an annular
cally opposite horns containing outlet holes, the air bores being connected to the supply bores, the supply bores being
15. A nozzle structure [as de?ned in claim 1] for a paint
slot surrounding the central outlet, the annular slot being 30
situated on at least one circle about a central axis of the
6. A nozzle structure as de?ned in claim 5, in Which the air
cap has at least one essentially axially parallel control bore betWeen the central axis and each of said horns. 7. A nozzle structure as de?ned in claim 6, in Which the air
35
40 bores are arranged on one or more circles about the central
of the air [reversing] de?ection disk, starting at a ?rst angle, folloWing at a second, smaller angle and ?nally being cylin drical to form a inside Wall of the annular slot. 9. A nozzle structure as de?ned in claim 5, and further including a paint spray gun on Which the nozzle structure is
45
10. A nozzle structure [as de?ned in claim 1] for a paint spray gun, comprising a central outlet for paint, an annular 50
a number of virtually axially parallel bores, the bores being situated on at least one circle about a central axis of the 55
disk toward the annular slot. 2]. A nozzle structure as defined in claim 1, wherein the
ously in the region of the annular slot until said Wall is paral 60
the air [reversing] de?ection disk is discontinuously inter rupted by a plane annular surface oriented at almost right angles to the central axis. 12. A nozzle structure as de?ned in claim 10, further
including a nozzle insert having axially parallel horn air
annular slot. 20. A nozzle structure as de?ned in claim 18, wherein the annular duct includes an outside tapered wall, and the edge
of the air de?ection disk is spaced from the outside wall to form an opening allowing air to?ow past the air de?ection
in Which an outside Wall of the annular duct tapers continu ously from the bores to the annular slot and curves continu
lel With the central axis. 11. A nozzle structure as de?ned in claim 10, Wherein the continuous tapering of the outside Wall in a direction toWard
area of turbulence in the ?ow of airfrom the bores to the annular slot. 19. A nozzle structure as de?ned in claim 18, wherein the annular duct includes an annular surface between the air
de?ection disk and the annular slotfor producing a second area of turbulence in the ?ow of airfrom the bores to the
connected inside the nozzle structure via an annular duct to
nozzle structure, means for providing compressed air via the bores for delivery to the annular duct, and an air de?ection disk located inside the annular duct and opposite the bores,
axis. 17. A nozzle structure as de?ned in claim 1, and further including a paint spray gun on Which the nozzle structure is mounted. 18. A nozzle structure as defined in claim 1, wherein the
air de?ection disk includes an edgeforproducing [a] the?rst
mounted.
slot surrounding the central outlet, the annular slot being
nozzle structure, means for providing compressed air via the bores for delivery to the annular duct, and an air de?ection disk located inside the annular duct and opposite the bores, Wherein the air reversing disk is made as a separate compo nent Which is mounted onto a paint nozzle that contains the bores and is retained by the nozzle structure. 16. A nozzle structure as de?ned in claim 1, Wherein the
cap has tWo essentially axially parallel control bores betWeen the central axis and each of said horns. 8. A nozzle structure as de?ned in claim 2, Wherein the inside Wall of the annular duct tapers conically in a direction
connected inside the nozzle structure via an annular duct to
a number ofvirtually axially parallel bores, the bores being
connected to the outlet holes, the outlet holes being directed to the central axis in a direction of flow toward the annular slot.
air de?ection disk includes an edge interrupting the ?ow of air exiting from the bores and distributing the air peripher ally around the annular duct. 22. A nozzle structure for a paint spray gun according to claim 1, wherein the annular duct includes an annular sur
65
face between the air de?ection disk and the annular slot for producing a second area ofturbulence in the?ow ofairfrom the bores to the annular slot.
US RE40,433 E 7
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23. A nozzle structure for a paint spray gun, comprising a central outletforpaint, an annular slot surrounding the cen
lar duct and opposite the bores, further including at apair of
tral outlet, the annular being connected inside the nozzle structure via an annular duct to a number of virtually axially parallel bores, the bores being situated on at least one circle about a central axis of the nozzle structure, means for pro
viding compressed air via the boresfor delivery to the annu lar duct, and an air de?ection disk located inside the annu
lar duct and opposite the bores, wherein the annular duct includes an inside wall and an outside tapered wall extend
ingfrom the air de?ection disk to the annular slot. 24. A nozzle structure for a paint spray gun, comprising a central outletforpaint, an annular slot surrounding the cen
tral outlet, the annular slot being connected inside the nozzle structure via an annular duct to a number of virtually axially parallel bores, the bores being situated on at least one circle about a central axis of the nozzle structure, means for pro
viding compressed air via the boresfor delivery to the annu lar duct, and an air de?ection disk located inside the annu
air jet horns, and least a pair of axial air control bores respectively on opposite sides of the annular slot and con
nected with the annular ductfor controlling the airjet horns, and wherein the air de?ection disk is disposed between the bores and the control bores to prevent the direct ?ow of air from the bores to the control bores. 25. A nozzle structure as de?ned in claim 24, wherein the
air de?ection disk includes an edge disposed in the path of the air?owfrom the boresforproducing air turbulence with tangential components that peripherally distribute the air around the annular duct. 26. A nozzle structure as de?ned in claim 24, wherein the
air de?ection disk includes an edge for homogenizing the pressure around the periphery of the annular duct.
